Terminal device, wireless communication device, wireless communication system and wireless communication method

Abstract

A terminal device includes a processor configured to autonomously select a first resource for transmission of data from among a plurality of resources; transmit the data with a first transmit mode to another terminal device by using the first resource; receive control information that has been transmitted from a wireless communication device capable of performing communication with the own terminal device and that designates a second resource that is not overlapped with the first resource; and retransmit the data with a second transmit mode to the other terminal device by using the second resource designated by the control information.

What is claimed is: 
     
         1 . A terminal device comprising:
 a processor configured to:
 autonomously select a first resource for transmission of data from among a plurality of resources; 
 transmit the data with a first transmit mode to another terminal device by using the first resource; 
 receive control information that has been transmitted from a wireless communication device capable of performing communication with the own terminal device and that designates a second resource that is not overlapped with the first resource; and 
 retransmit the data with a second transmit mode to the other terminal device by using the second resource designated by the control information. 
   
     
     
         2 . The terminal device according to  claim 1 , wherein the wireless communication device is a base station device or a management terminal device that manages the terminal device and the other terminal device. 
     
     
         3 . The terminal device according to  claim 1 , wherein, when the control information that designates the second resource is not received before a predetermined period of time has elapsed after an initial transmission of the data, the processor is further configured to autonomously select a third resource for retransmission of the data from among the plurality of resources and retransmit the data by using the third resource. 
     
     
         4 . The terminal device according to  claim 1 , wherein, when the control information that designates the second resource is not received before a predetermined period of time has elapsed after an initial transmission of the data, the processor is further configured to stop retransmitting the data. 
     
     
         5 . The terminal device according to  claim 1 , wherein the processor is further configured to transmit control information indicating a location of the first resource to the other terminal device, wherein
 the control information indicating the location of the first resource is detected by the wireless communication device, and   the wireless communication device judges whether reception quality of the data in the other terminal device is favorable by using the control information indicating the location of the first resource and transmits, when the reception quality of the data is not favorable, control information that designates the second resource.   
     
     
         6 . The terminal device according to  claim 5 , wherein the processor is further configured to transmit the control information indicating the location of the first resource to the wireless communication device via a control channel of an uplink or a sidelink. 
     
     
         7 . The terminal device according to  claim 1 , wherein
 the processor is further configured to receive the control information that has been transmitted from the wireless communication device and that designates the second resource or control information that has been transmitted from the wireless communication device and that designates autonomous selection of a third resource for retransmission of the data, and   when the control information that designates autonomous selection of the third resource is received, the processor is further configured to autonomously select the third resource from among the plurality of resources and retransmit the data by using the third resource.   
     
     
         8 . A wireless communication device comprising:
 a processor configured to:
 judge, when a terminal device capable of performing communication with the own wireless communication device transmits data with a first transmit mode to another terminal device by using a first resource, whether reception quality of the data in the other terminal device is favorable; 
 select, when it is judged that the reception quality of the data is not favorable, a second resource that is used by the terminal device to retransmit the data with a second transmit mode and that is not overlapped with the first resource; and 
 transmit control information that designates the second resource to the terminal device. 
   
     
     
         9 . The wireless communication device according to  claim 8 , wherein the wireless communication device is a base station device or a management terminal device that manages the terminal device and the other terminal device. 
     
     
         10 . The wireless communication device according to  claim 8 , wherein
 when it is judged that the reception quality of the data is favorable, the processor is further configured to stop selecting the second resource, and   when selection of the second resource is stopped, the processor is further configured to transmit control information that designates autonomous selection of a third resource for retransmission of the data to the terminal device.   
     
     
         11 . The wireless communication device according to  claim 8 , wherein
 a first resource pool to which the first resource belongs and a second resource pool to which the second resource belongs are split from a common resource pool that has a constant size,   the processor is further configured to simultaneously have a first transmit mode with the first resource pool, and have a second transmit mode with the second resource pool, and   the processor is further configured to change a ratio of a size of the first resource pool to a size of the second resource pool at predetermined timing.   
     
     
         12 . A wireless communication system comprising:
 a wireless communication device;   a first terminal device; and   a second terminal device, wherein   the first terminal device includes a processor is configured to:
 autonomously select a first resource configured with a first transmit mode for transmission of data from among a plurality of resources, 
 transmit the data to the second terminal device by using the first resource, 
 receive control information that has been transmitted from the wireless communication device and that designates a second resource configured with a second transmit mode that is not overlapped with the first resource, and 
 retransmit the data to the second terminal device by using the second resource designated by the control information, and 
   the wireless communication device includes a processor is configured to:
 judge whether reception quality of the data in the second terminal device is favorable, 
 select the second resource when it is judged that the reception quality of the data is not favorable, and 
 transmit the control information that designates the second resource to the first terminal device. 
   
     
     
         13 . A wireless communication method used in a wireless communication system that includes a wireless communication device, a first terminal device, and a second terminal device, the wireless communication method comprising:
 selecting autonomously, performed by the first terminal device, a first resource configured with a first transmit mode for transmission of data from among a plurality of resources;   transmitting, performed by the first terminal device, the data to the second terminal device by using the first resource;   receiving, performed by the first terminal device, control information that has been transmitted from the wireless communication device and that designates a second resource configured with a second transmit mode that is not overlapped with the first resource;   retransmitting, performed by the first terminal device, the data to the second terminal device by using the second resource designated by the control information;   judging, performed by the wireless communication device, whether the reception quality of the data in the second terminal device is favorable;   selecting, performed by the wireless communication device, the second resource when it is judged that the reception quality of the data is not favorable; and   transmitting, performed by the wireless communication device, the control information that designates the second resource to the first terminal device.